DNA methylation epigenotypes in Breast Cancer Molecular Subtypes

Analysis of luminal A, luminal B, cerbB2+ and basal-like breast cancer subtypes' methylation profiles. The hypothesis tested in the present study was that tumor subtype specific aberrant methylation profiles might be inductors of some transcriptional changes taking place in breast cancer molecular subtypes. Results clearly demonstrate the differences in the methylation profiles of basal-like and HER2-overexpressing tumors and provide compelling evidence to support the utilization of this biomarker for prognostication and therapeutic stratification of patients with breast cancer. DNA methylation profiling analysis at 1537 CpG loci was performed in 28 paired breast cancer/adjacent tissues representing the four major breast cancer subtypes, plus four more non-affected tissue of which two were peritumoral, i.e. surrounding the tumor, and two corresponded to the adjacent area, i.e. more than 2 cm away from the tumor.